Risk model for deaths and renal replacement therapy dependence in patients with acute kidney injury after cardiac surgery

Incidence of Acute Kidney Injury and Risk Factors of Prognosis in Patients with Acute Stanford Type A Aortic Dissection

PURPOSE

We aimed to investigate the prognosis and impact of postoperative acute kidney injury (AKI) in acute Stanford type A aortic dissection (ATAAD) patients, and to analyze the predictors of short- and medium-term survival.

METHODS

A total of 192 patients who underwent ATAAD surgery were included between May 2014 and May 2019. Perioperative data of these patients were analyzed. All of the discharged patients were followed up for 2 years.

RESULTS

Postoperative AKI was identified in 43 of 192 patients (22.4%). The two-year survival rate of patients with AKI after discharge was 88.2% and that without AKI was 97.2%.The difference was statistically significant (χ2 = 5.355, log-rank P = 0.021). Cox hazards regression showed that age (hazard ratio [HR], 1.070; P = 0.002), cardiopulmonary bypass (CPB) time (HR, 1.026; P = 0.026), postoperative AKI (HR, 3.681; P = 0.003), and red blood cell transfusion (HR, 1.548; P = 0.001) were independent risk factors for the short- and medium-term total mortality of ATAAD patients.

CONCLUSION

The incidence of postoperative AKI is high in ATAAD, and the mortality of patients with AKI increases significantly within 2 years. Age, CPB time, and red blood cell transfusion were also independent risk factors for short-and medium-term prognoses.

Intraoperative hemodialysis during open-heart surgery in patients with severe chronic kidney disease: a retrospective cohort study

Background

Acute kidney injury and chronic kidney disease (CKD) after cardiac surgery are associated with poor renal prognosis and increased mortality. The impact of intraoperative hemodialysis (IHD) on postoperative renal function remains unknown. We aimed to evaluate the utility of IHD during open-heart surgery in patients with severe non-dialysis-dependent chronic kidney disease (CKD-NDD) and its association with clinical outcomes.

Methods

This was a single-center retrospective cohort study that employed IHD during non-emergency open-heart surgery in patients with CKD stage G4 or G5. Patients who underwent emergent surgery, chronic dialysis, and/or kidney transplantation were excluded. We retrospectively compared the clinical characteristics and outcomes between patients from the IHD and non-IHD groups. The primary outcomes were 90-day mortality and postoperative initiation of renal replacement therapy (RRT).

Results

Twenty-eight patients were categorized into the IHD group and 33 into the non-IHD group. When comparing the IHD and non-IHD groups, men accounted for 60.7 vs. 50.3% of patients, the mean patient age was 74.5 (standard deviation [SD] 7.0) vs. 72.9 (SD 9.4) years (p = 0.744), and the proportion of patients with CKD G4 was 67.9 vs. 84.9% (p = 0.138). Regarding clinical outcomes, no significant differences were observed in the 90-day mortality (7.1 vs. 3.0%; p = 0.482) and 30-day RRT (17.9 vs. 30.3%; p = 0.373) rates between the groups. Among the patients with CKD G4, the IHD group had significantly lower 30-day RRT rates than the non-IHD group (0 vs. 25.0%; p = 0.032). RRT initiation was less likely for patients with CKD G4 (odds ratio 0.07, 95% confidence interval [CI] 0.01–0.37; p = 0.002); however, IHD did not significantly decrease the incidence of poor clinical outcomes (odds ratio 0.20, 95% CI 0.04–1.07; p = 0.061).

Conclusions

IHD during open-heart surgery in patients with CKD-NDD did not improve their clinical outcomes with regards to postoperative dialysis. However, for patients with CKD G4, IHD may be useful for postoperative cardiac management.

Optimal timing of renal replacement therapy for favourable outcome in patients of acute renal failure following cardiac surgery

Objectives

Acute renal failure is a serious complication following cardiac surgery. This may lead to fatal outcome if not treated timely. Continuous renal replacement therapy (RRT) has shown improvement in outcome. There is no clear consensus on the timing of the initiation of RRT in these patients. This study evaluates the factors predicting favourable outcome in this group of patients.

Methods

Patients undergoing cardiac surgery between January 2015 and December 2018 are included in this retrospective study. RRT is required in 24 patients out of 2254 operated during this period. Patients are divided into groups, survivors (group 1, n = 8) and dead (group 2, n = 16). The preoperative information is accessed from the hospital information system and intensive care unit data. Multivariate analysis of pre continuous renal replacement therapy (CRRT) bicarbonate level, pH, potassium, time of initiating CRRT and central venous pressure is performed.

Results

The incidence of acute renal failure requiring RRT is 1.06%. Patients in two groups were similar in demographics and presence of risk factors. There was difference in the pre RRT bicarbonate level (p = 0.007). On multivariate analysis, pre RRT bicarbonate levels predict survival (p = 0.003). ROC curve for pre RRT bicarbonate predicts survival for value above 16.83 mg/dl with 80% sensitivity and 78.6% specificity.

Conclusion

Bicarbonate level in blood predicts the best evidence for initiating the renal replacement therapy in of acute renal failure following cardiac surgery. When urine output drops to < 0.5 ml/kg and not responding to infusion of furosemide, RRT must be initiated at sodium bicarbonate in blood above 16.9 mg%.

Acute Kidney Injury Associated with Cardiac Surgery: a Comprehensive Literature Review

Objective

To comprehensively understand cardiac surgeryassociated acute kidney injury (CSA-AKI) and methods of prevention of such complication in cardiac surgery patients.

Methods

A comprehensive literature search was performed using the electronic database to identify articles describing acute kidney injury (AKI) in patients that undergone cardiac surgery. There was neither time limit nor language limit on the search. The results were narratively summarized.

Results

All the relevant articles have been extracted; results have been summarized in each related section. CSA-AKI is a serious postoperative complication and it can contribute to a significant increase in perioperative morbidity and mortality rates. Optimization of factors that can reduce CSA-AKI, therefore, contributes to a better postoperative outcome.

Conclusion

Several factors can significantly increase the rate of AKI; identification and minimization of such factors can lead to lower rates of CSA-AKI and lower perioperative morbidity and mortality rates.

Risk Factors for Acute Kidney Injury in Hospitalized Non-Critically Ill Patients: A Population-Based Study

OBJECTIVE

To develop and validate an acute kidney injury (AKI) risk prediction model for hospitalized non-critically ill patients.

PATIENTS AND METHODS

We retrospectively identified all Olmsted County, Minnesota, residents admitted to non-intensive care unit (ICU) wards at Mayo Clinic Hospital, Rochester, Minnesota, in 2013 and 2014. The cohort was divided into development and validation sets by year. The primary outcome was hospital-acquired AKI defined by Kidney Disease: Improving Global Outcomes criteria. Cox regression was used to analyze mortality data. Comorbid risk factors for AKI were identified, and a multivariable model was developed and validated.

RESULTS

The development and validation cohorts included 3816 and 3232 adults, respectively. Approximately 10% of patients in both cohorts had AKI, and patients with AKI had an increased risk of death (hazard ratio, 3.62; 95% CI, 2.97-4.43; P<.001). Significant univariate determinants of AKI were preexisting kidney disease, diabetes mellitus, hypertension, heart failure, vascular disease, coagulopathy, pulmonary disease, coronary artery disease, cancer, obesity, liver disease, and weight loss (all P<.05). The final multivariable model included increased baseline serum creatinine value, admission to a medical service, pulmonary disease, diabetes mellitus, kidney disease, cancer, hypertension, and vascular disease. The area under the receiver operating characteristic curves for the development and validation cohorts were 0.71 (95% CI, 0.69-0.75) and 0.75 (95% CI, 0.72-0.78), respectively.

CONCLUSION

Hospital-acquired AKI is common in non-ICU inpatients and is associated with worse outcomes. Patient data at admission can be used to identify increased risk; such patients may benefit from more intensive monitoring and earlier intervention and testing with emerging biomarkers.